This report deals with the incident in the North Sea during
the night of 20/21 June 1940 (the data used by authors Edmund Kosiarz and
Czeslaw Rudzki was from 20/21 June. The data used by Mariusz Borowiak was from
19-20 June) when the Polish Submarine Wilk collided with something.
Several books have been published, variously suggesting that Wilk hit a
submarine, or a mine, or even a surface wreck. The fact that there are two
different official versions of Wilk`s collision with an object, makes
the matter more difficult to resolve. It is worth mentioning that foreign
writers invariably state the theory that Wilk hit the Dutch submarine
O-13. Polish authors contend that
Wilk hit the German U-122.

In my opinion, no-one has given a convincing reason for believing that
Wilk hit one submarine or the other.

The lack of unanimity aroused my curiosity, and I determined to investigate
this intriguing mystery as best I could, to establish whether it might be
possible to reach a conclusion on the basis of all the available information I
could unearth.

I have been researching this interesting theme since August
1997, and have found many interesting facts about this case. This first part
deals with the story of Boleslaw Romanowski, First Officer of Wilk who
was on watch in the conning tower when the collision happened. Romanowski
wrote a book and articles about his memoirs during war, so we have a basic
source for his version.

Romanowski's Version.

"I had the night watch until 04.00hrs. The night was dark and
the sea very peaceful[...]
We were only doing 3 knots, so as not to leave a trace behind us. I was at my
usual position on the left side of the conning tower, with powerful Barr and
Stroud binoculars. The signalman was watching from the right side of the
conning tower, and another officer was looking out beyond our stern. It was
very quiet[...]

Suddenly the signalman shouted loudly:
-10 degrees, a ship!!
I immediately saw the prow of a small ship. The distance was about 300 meters
- too close to fire torpedoes.
"Collide" I decided quickly.
- Hard left! I shouted. - Full speed ahead! I said without taking my eyes off
the observed thing.
The diesels suddenly roared loudly. Wilk was slowly picking up speed.
- It's a U-boat! shouted the signalman.
At the same time, I saw the characteristic silhouette of a submarine.
Increase speed quickly! I shouted, - It is diving!!Wilk was increasing speed and we could see the enemy boat desperately
diving to avoid the imminent collision.

After reaching a speed of only 9 knots, the collision
occurred. Our bow hit the U-boat in front of her deck gun, just as her deck
had disappeared under water and her conning tower was about to submerge. The
impact was very powerful. Under my legs I felt a violent shudder, and heard a
loud noise and also another strange noise too.

Looking behind I saw that the U-boat had disappeared from the
surface, and only a lot of white foam could be seen, but it is difficult to
say if the foam was coming from the rammed deck of the U-boat or from her
quick diving.
- What happened? Shouted the captain, (Boris Karnicki), who had rushed to the
conning tower.
- We ran down a U-boat sir!!![...]

The U-boat was more visible to us than we were to them, as we
could see all of her silhouette, but they could see only our bow.
The German saw us at the last moment and made the tragic mistake of diving,
instead of remaining on the surface and avoiding the collision by turning
left. If we hit her deck, she was probably sunk. Who knows, maybe we turned
her upside down and finished her off with our propellers.
But our propellers probably hit the U-boat's conning tower.

All night, and for weeks afterwards, the crew discussed the
incident and wondered if the U-boat had been sunk, or was safe somewhere on
the sea."

From the left to the right
D.Th baron Mackay
#1, Romanowski #2, Capt William Keay #3, Unknown #4,
J.F. van Dulm #5. Dundee
1940/41.
Click here
for more info on this image

According to Romanowski's version, it is more likely that
Wilk hit a U-boat rather than a Dutch submarine.

The Facts.

Let us examine the facts: The important factors are the diving
time and the deck-gun.

The Diving Time.

It is known that German U-boats had a big advantage in that they could dive
very quickly - in less than 30-35 seconds - unlike Allied submarines which
took 50 seconds or more to dive. U-122 was a new type IXB
U-boat, commissioned on 30 March 1940. O-13, which was commissioned in
the Royal Dutch Navy on 31 October 1931, took much longer to dive.

If we consider Romanowski’s statement that Wilk was 300 meters away
from the unknown submarine, and that the enemy's captain saw the Wilk
at the last moment and decided to dive, it is obvious that the submarine which
was spotted must have had an ability to dive very quickly.
It is worth remembering that Wilk collided with the other submarine
while Wilk’s speed was still only 9 knots - a detail that proves how
close Wilk and the other submarine were. 300 meters is a not a great
distance. Wilk probably reached the other submarine in less than one
minute - if not less than 40-50 seconds. (In fact, at 9 knots, it would have
taken 65 seconds to cover 300 meters, but as Wilk was accelerating from
only 3 knots, it would have taken her a bit longer than this to cover the 300
meters).

If Ltz. I
E.H.Vorster, the Dutch commander of
O-13, had seen Wilk at the last moment, he would have realized
that it would be impossible for him to dive in time to avoid a collision, but
with his quicker diving time, a German U-boat commander could make that risky
decision, which was to prove fatal.

The Dutch submarine O-13 would not have had a chance to dive, and
even if her captain did decide to dive, Wilk would have hit O-13
while she was still on the surface, and not disappearing quickly under the
water, as Romanowski described.

The Deck-Gun.

Romanowski and the others on Wilk's conning tower
stated that they saw a deck-gun on the submarine they rammed. O-13 did
not have a deck-gun!!! (But U-122 did!). O-13 had two 40mm
anti-aircraft guns on the front of the conning tower.

O 13, note the anti-aircraft
guns and the absence of a deck-gun.

Another more interesting photo of O-13,
courtesy of the Naval Historical Section, Royal Netherlands Navy, is published
in Anthony J. Watts’ book "Allied Submarines". A caption above the photo says:
"Note the lack of a deck gun, and hatches protecting retractable 40mm mounts
in fore and aft extensions of the conning tower."
In fact in this photograph, O-13’s small guns are hidden, and no gun is
visible in the conning tower, unlike the photograph above.

Some might say that Romanowski may have misidentified these anti-aircraft
guns on her conning tower as a deck gun, but he was an experienced submariner,
and is unlikely to make such a mistake. He was closely watching the unknown
submarine all the time through binoculars, and could see her full silhouette
from a distance of 300 meters. His view of the other submarine must also have
improved as the Wilk closed to ram.

On the other hand O-13 could have hidden her 2x40mm guns. No one said that
when a submarine surfaces, and at nights mainly, she must have her guns out of
the hatches.

The Pennant Number.

All Dutch submarines, with the single exception of O-13, had pennant numbers painted on
the conning tower when the Royal Dutch Navy was operating from Great Britain.

The number "O-13" is clearly visible on the conning tower in the
photograph in Watts’ book, but may later have been painted out.

(For some reason which is not clear to me at the moment, O-13 had
her pennant number changed to N-13, and this is the number she was
displaying when she left Dundee for her last patrol).

We know that some U-boats had numbers and/or emblems painted on the conning
tower, while others did not. Pre-war photographs of U-boats, and those taken
early in the war, show pennant numbers painted on the conning tower, but at
some time during the war, the Germans must have made a decision to stop
painting the numbers on the tower, as later photographs do not show numbers.

Neither Romanowski nor anyone else mentioned seeing a pennant number, or
any other identifying symbol on the conning tower. If there had been such
markings, surely Romanowski would have mentioned it. The fact that he did not,
suggests that nothing was painted on the conning tower of the unidentified
submarine.

Most Likely a U-Boat

These were the important and basic details of how Wilk hit - very
likely 99% certainly - a U-boat, and not a Dutch submarine.

But things are not so simple. We have also another version of the collision
that we will discuss in the second part. And also we will consider the
possible positions of the both submarines (U-122 and O-13) since
nothing is clear about U-122’s route..

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